! Layer 5 — Sovereign IDE Syntax Highlighting
! Query compiler + theme mapping
! Maps to: snapkitty-resonance-bridge token stream structure
MODULE sovereign_syntax
  USE iso_c_binding
  USE sovereign_runtime, ONLY: runtime_panic, str_intern
  USE sovereign_parser,  ONLY: parser_ctx_t, cst_node_t
  IMPLICIT NONE
  PRIVATE

  ! ── Color IDs (theme slots) ───────────────────────────────────────────────
  INTEGER, PARAMETER :: COLOR_DEFAULT    = 0
  INTEGER, PARAMETER :: COLOR_KEYWORD    = 1
  INTEGER, PARAMETER :: COLOR_IDENTIFIER = 2
  INTEGER, PARAMETER :: COLOR_STRING     = 3
  INTEGER, PARAMETER :: COLOR_NUMBER     = 4
  INTEGER, PARAMETER :: COLOR_COMMENT    = 5
  INTEGER, PARAMETER :: COLOR_OPERATOR   = 6
  INTEGER, PARAMETER :: COLOR_TYPE       = 7
  INTEGER, PARAMETER :: COLOR_FUNCTION   = 8
  INTEGER, PARAMETER :: COLOR_ERROR      = 9
  INTEGER, PARAMETER :: N_COLORS         = 10

  ! ── Theme ─────────────────────────────────────────────────────────────────
  ! RGBA packed as 0xRRGGBBAA
  TYPE :: theme_t
    INTEGER(C_INT32_T) :: colors(N_COLORS)
    LOGICAL            :: worm_sealed = .FALSE.
  END TYPE theme_t

  ! ── Highlight span ────────────────────────────────────────────────────────
  INTEGER, PARAMETER :: MAX_SPANS = 131072
  TYPE :: span_t
    INTEGER :: start_byte = 0
    INTEGER :: end_byte   = 0
    INTEGER :: color_id   = COLOR_DEFAULT
  END TYPE span_t

  TYPE :: span_list_t
    TYPE(span_t) :: spans(MAX_SPANS)
    INTEGER      :: count = 0
  END TYPE span_list_t

  ! ── Query ─────────────────────────────────────────────────────────────────
  INTEGER, PARAMETER :: MAX_QUERY_PATTERNS = 256
  TYPE :: query_pattern_t
    INTEGER(C_INT32_T) :: node_kind_id = 0
    INTEGER            :: color_id     = COLOR_DEFAULT
  END TYPE query_pattern_t

  TYPE :: query_t
    TYPE(query_pattern_t) :: patterns(MAX_QUERY_PATTERNS)
    INTEGER               :: pattern_count = 0
  END TYPE query_t

  PUBLIC :: syntax_init
  PUBLIC :: syntax_load_theme
  PUBLIC :: syntax_highlight
  PUBLIC :: syntax_highlight_incremental
  PUBLIC :: theme_default_sovereign_dark

CONTAINS

  ! ---------------------------------------------------------------------------
  SUBROUTINE syntax_init()
    WRITE(*,'(A)') '[syntax] init'
  END SUBROUTINE syntax_init

  ! ---------------------------------------------------------------------------
  ! Load a theme; WORM-seal after load
  SUBROUTINE syntax_load_theme(theme, path)
    TYPE(theme_t),    INTENT(INOUT) :: theme
    CHARACTER(LEN=*), INTENT(IN)    :: path
    ! TODO: parse theme file (JSON/TOML)
    CALL theme_default_sovereign_dark(theme)
    theme%worm_sealed = .TRUE.
    WRITE(*,'(A,A)') '[syntax] theme loaded from ', TRIM(path)
  END SUBROUTINE syntax_load_theme

  ! ---------------------------------------------------------------------------
  ! Sovereign dark theme — matches bob-ide color palette
  SUBROUTINE theme_default_sovereign_dark(theme)
    TYPE(theme_t), INTENT(INOUT) :: theme
    theme%colors(COLOR_DEFAULT+1)    = INT(Z'D4D4D4FF', C_INT32_T)  ! #D4D4D4
    theme%colors(COLOR_KEYWORD+1)    = INT(Z'569CD6FF', C_INT32_T)  ! #569CD6
    theme%colors(COLOR_IDENTIFIER+1) = INT(Z'9CDCFEFF', C_INT32_T)  ! #9CDCFE
    theme%colors(COLOR_STRING+1)     = INT(Z'CE9178FF', C_INT32_T)  ! #CE9178
    theme%colors(COLOR_NUMBER+1)     = INT(Z'B5CEA8FF', C_INT32_T)  ! #B5CEA8
    theme%colors(COLOR_COMMENT+1)    = INT(Z'6A9955FF', C_INT32_T)  ! #6A9955
    theme%colors(COLOR_OPERATOR+1)   = INT(Z'D4D4D4FF', C_INT32_T)
    theme%colors(COLOR_TYPE+1)       = INT(Z'4EC9B0FF', C_INT32_T)  ! #4EC9B0
    theme%colors(COLOR_FUNCTION+1)   = INT(Z'DCDCAAFF', C_INT32_T)  ! #DCDCAA
    theme%colors(COLOR_ERROR+1)      = INT(Z'F44747FF', C_INT32_T)  ! #F44747
    theme%worm_sealed = .FALSE.
  END SUBROUTINE theme_default_sovereign_dark

  ! ---------------------------------------------------------------------------
  ! Full highlight pass over entire CST
  SUBROUTINE syntax_highlight(ctx, spans, query)
    TYPE(parser_ctx_t), INTENT(IN)    :: ctx
    TYPE(span_list_t),  INTENT(INOUT) :: spans
    TYPE(query_t),      INTENT(IN)    :: query
    spans%count = 0
    CALL highlight_node(ctx, ctx%root, spans, query)
    WRITE(*,'(A,I0,A)') '[syntax] highlight: ', spans%count, ' spans'
  END SUBROUTINE syntax_highlight

  ! ---------------------------------------------------------------------------
  ! Incremental highlight — only reprocess changed CST subtree
  SUBROUTINE syntax_highlight_incremental(ctx, spans, query, from_node)
    TYPE(parser_ctx_t), INTENT(IN)    :: ctx
    TYPE(span_list_t),  INTENT(INOUT) :: spans
    TYPE(query_t),      INTENT(IN)    :: query
    INTEGER,            INTENT(IN)    :: from_node
    ! TODO: invalidate spans overlapping from_node range, re-run from there
    CALL highlight_node(ctx, from_node, spans, query)
  END SUBROUTINE syntax_highlight_incremental

  ! ── Internal ──────────────────────────────────────────────────────────────

  RECURSIVE SUBROUTINE highlight_node(ctx, idx, spans, query)
    TYPE(parser_ctx_t), INTENT(IN)    :: ctx
    INTEGER,            INTENT(IN)    :: idx
    TYPE(span_list_t),  INTENT(INOUT) :: spans
    TYPE(query_t),      INTENT(IN)    :: query
    INTEGER :: i, color, child
    IF (idx == 0) RETURN
    ! Match node kind against query patterns
    color = COLOR_DEFAULT
    IF (ctx%nodes(idx)%is_error) THEN
      color = COLOR_ERROR
    ELSE
      DO i = 1, query%pattern_count
        IF (query%patterns(i)%node_kind_id == ctx%nodes(idx)%kind) THEN
          color = query%patterns(i)%color_id
          EXIT
        END IF
      END DO
    END IF
    ! Emit span if leaf
    IF (ctx%nodes(idx)%n_children == 0) THEN
      IF (spans%count < MAX_SPANS) THEN
        spans%count = spans%count + 1
        spans%spans(spans%count)%start_byte = ctx%nodes(idx)%start_byte
        spans%spans(spans%count)%end_byte   = ctx%nodes(idx)%end_byte
        spans%spans(spans%count)%color_id   = color
      END IF
      RETURN
    END IF
    ! Recurse into children
    DO i = 1, ctx%nodes(idx)%n_children
      child = ctx%nodes(idx)%children(i)
      CALL highlight_node(ctx, child, spans, query)
    END DO
  END SUBROUTINE highlight_node

END MODULE sovereign_syntax